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Biomedical subjects

W M Mendenhall

Publications and source records attributed to W M Mendenhall.

At least 19 recordsLinked to original sources
PubMed1992

The influence of dose and time on wound complications following post-radiation neck dissection.

Data on 205 patients who were treated with a planned unilateral neck dissection following radiation therapy were analyzed with the purpose of understanding how treatment factors affect the incidence of wound complications. There were 27 occurrences of wound complication in the patient series. Logistic regression was used to analyze the data. We found that the surgical technique of flap reconstruction gave a significant increase in wound complications. There was a suggestion, although not statistically significant, that higher total doses increased the complication rate, that lower fraction sizes reduced the complication rate, and that longer overall radiotherapy treatment times were associated with higher complication rates. There was no association between the incidence of complications and the time interval between the end of radiotherapy and surgery.

Carcinoma, Squamous Cell↗
PubMed1992

Stage T3 squamous cell carcinoma of the glottic larynx: a comparison of laryngectomy and irradiation.

One-hundred eighteen patients with previously untreated T3 squamous cell carcinoma of the glottic larynx were treated with curative intent between March 1965 and November 1988 at the University of Florida. All patients were observed for at least 2 years and 83% were observed for 5 or more years. Fifty-three patients were treated with irradiation alone and 65 patients were treated with surgery alone (32) or combined with irradiation (33). Thirty-two patients treated with irradiation alone had twice-daily fractionation and the remainder had once-daily fractionation. The local-regional control rates, including patients successfully salvaged after a local-regional recurrence, were 81% after irradiation alone and 81% after surgery alone or combined with adjuvant irradiation. The local control rates for patients treated with irradiation alone were 53% after once-daily fractionation and 71% after twice-daily fractionation. There was no relationship between vocal cord mobility at 5000 cGy, at the end of radiotherapy, or at 1 month after treatment and subsequent local control. The 5-year cause-specific survival rates were 74% for patients treated with irradiation alone and 63% for patients treated surgically. The incidence of severe complications, including those associated with salvage procedures, was 15% for both treatment groups. The rates of laryngeal voice preservation were 66% after irradiation alone and 2% after surgery. Irradiation alone for selected patients with T3 glottic cancer resulted in similar rates of local-regional control, survival, and severe complications, with a significantly higher likelihood of voice preservation, compared with surgery.

Carcinoma, Squamous Cell↗
PubMed1992

Does neck stage influence local control in squamous cell carcinomas of the head and neck?

Recently, reports have suggested that the probability of local control of head and neck cancers treated with radiotherapy alone is inversely related to the extent of neck node disease at presentation. This has led some to conclude that primary lesions in patients with neck node metastases should be treated more aggressively than lesions of the same T stage in patients presenting with a clinically negative neck. We reviewed the records of 607 patients with squamous cell carcinoma of the head and neck to determine the relationship between the extent of neck node disease at diagnosis and the probability of tumor control at the primary site. All patients were treated with continuous-course irradiation alone to the primary site and have a minimum follow-up of 2 years. Mucosal sites analyzed included the oropharynx (soft palate, tonsillar region, base of tongue), hypopharynx (pharyngeal wall, pyriform sinus), and supraglottic larynx. Patients with simultaneous primary lesions were excluded from the analysis. Parameters tested included T stage, N stage, and fractionation (once daily or twice daily). For statistical analyses, N stage was grouped as N0, N1, N2A-N3A, and N2B-N3B. Local control was analyzed using a multivariate analysis, the forward stepwise long-rank test of association of covariates. Multivariate analyses revealed that the following parameters significantly influenced local control: oropharynx, T stage only (p = .0010); hypopharynx, T stage (p = .001) and twice-daily fractionation (p = .0031); and supraglottic larynx, T stage only (p = .0002). No significant correlation was found between neck stage and primary tumor control on univariate or multivariate analyses. Our data do not support the conclusion that primary lesions are controlled less often in patients with clinically positive neck nodes.

Carcinoma, Squamous Cell↗
PubMed1992

Radiation therapy for skin cancer near the eye: kilovoltage x-rays versus electrons.

When skin cancer near the eye is irradiated, a corneal shield is placed between the lids and globe to protect ocular structures. The effectiveness of the shield was evaluated with 250 kVp x-ray and 6-20 MeV electron beams. To simulate the clinical situation, a face phantom was constructed out of solid pieces of water-equivalent epoxy. In the region of the eye the phantom was milled to the exact contour of a human face. The phantom was used to reconstruct the setup that had been used to treat a patient with a 1-cm basal cell carcinoma of the mid portion of the lower lid. A medium-sized corneal shield (2-mm-thick lead plated with 0.1 mm gold) was placed on the eye portion of the phantom. A contoured lead (6 mm thick) face mask was placed on the surface of the phantom to define a 3-cm diameter radiation field that included only the inferior hemisphere of the shield. The doses that the cornea, lens, and retina would receive beneath the midpoint of the inferior hemisphere of the shield were measured using thermoluminescent and film dosimetry. With 6 to 8 MeV electrons, the corneal dose was 2 to 4 times higher than with 250 kVp x-rays. Corneal and lens doses rose rapidly with increasing electron beam energy such that with greater than 8 MeV the shield would provide relatively poor ocular protection. A scanning ion chamber and film dosimetry were used to determine the isodose profiles of 250 kVp x-ray and 6 MeV electron beams for a 3-cm diameter field collimated on the surface. With 250 kVp x-rays the 95% isodose area was 32% wider than with 6 MeV electrons. The ease of shielding and the ability to minimize field size argue in favor of kilovoltage x-rays for early-stage skin cancer near the eye.

Costs and Cost Analysis↗
PubMed1992

Stage IB or IIA-B carcinoma of the intact uterine cervix treated with irradiation: a multivariate analysis.

Although treatment results for Stage IB-IIA-B carcinoma of the cervix are generally stratified only by stage, several authors have found that other parameters such as tumor size, patient age, histology, and pretreatment hematocrit may influence pelvic control and/or survival. This is an analysis of 306 patients with carcinoma of the cervix treated with irradiation alone at the University of Florida between October 1964 and June 1984. Results were analyzed for the end points of pelvic control, distant metastasis, relapse-free survival, and overall survival. Stage for stage, there was a decrease of at least 20 percentage points in pelvic control rates of tumors greater than or equal to 6 cm versus those of tumors 0 to 3 cm in diameter, by univariate analysis; a similar pattern was also observed for the end point of relapse-free survival. When patients were stratified by Stages IB-IIA (greater than or equal to 6 cm and less than 6 cm) and IIB (greater than or equal to 6 and less than 6 cm), there was a clear pattern of improved pelvic control and relapse-free survival for patients over 50 years old and for patients with pretreatment hematocrits greater than 40%. The parameters of stage, tumor size, patient age, histology, and pretreatment hematocrit were evaluated in a multivariate analysis. For the end points of pelvic control, distant metastasis, and relapse-free survival, only tumor size was of independent prognostic significance for all three end points with p-values of 0.022, 0.003, and 0.0006, respectively. Stage did not show independent prognostic significance for any of these end points with p-values of 0.257, 0.878, and 0.284, respectively. The data suggest that tumor size is an important prognostic factor and should be incorporated into the reporting of cervical cancer treatment results.

Adenocarcinoma↗
PubMed1992

Dose, time, and fraction size issues for late effects in head and neck cancers.

This paper contains a statistical analysis of the dose-time factors influencing late complications in 784 patients with squamous cell carcinomas of the pharynx or larynx treated with external beam irradiation only at the University of Florida. The patients include 560 who received continuous course once-a-day therapy, 116 who received twice-a-day treatment, and 108 who received a once-a-day split course regimen. Both 2+ and 3+ complications were considered. Fifty-six patients developed either of these complications. The factors included in the analysis were site and size of the primary, total dose, fraction size, and treatment time. The linear-quadratic model was used to incorporate fraction size into the analysis. Proportional hazards analysis, which models the time to occurrence of the late complication, was used to quantify the joint influence of the above patient and fractionation variables on the incidence of late effects. The occurrence of the late effects was heterogeneous, with only a weak relationship to the patient and fractionation variables. The influence of the size of the primary was significant, with larger primaries associated with higher complication rates independent of fractionation variables. For oropharynx primary sites there was no significant effect of the fractionation variables. For larynx and hypopharynx, excluding T1-T2 true vocal cord, there was a significant effect of total dose and fraction size. The alpha/beta ratio was estimated to be 7.8 Gy (95% confidence interval, 3.0, infinity). There was no significant effect of overall treatment time. The estimated 2+ complication rate at 1 year from 68 Gy given in 2 Gy fractions in 50 days is 0.1% for T 1-2 vocal cord, 4.1% for T1-T2 supraglottic larynx, 3.8% for T3 supraglottic larynx and vocal cord, 14.9% for T4 supraglottic larynx, 6.7% for T1-T2 tonsil and soft palate, 7.6% for T3-T4 tonsil and soft palate, 7.0% for T1-T2 pyriform sinus and pharyngeal wall, and 13.0% for T3-T4 pyriform sinus and pharyngeal wall.

Carcinoma, Squamous Cell↗
PubMed1992

Does preoperative radiation therapy enhance the probability of local control and survival in high-risk distal rectal cancer?

One hundred forty-eight patients were treated with preoperative radiation therapy and surgery for resectable rectal adenocarcinoma at the University of Florida between 1975 and 1986. All patients had at least 5 years' follow-up; no patient was lost to follow-up. Three treatment protocols were used over the study period: 1975 to 1978, 3500 cGy in 20 fractions; 1979 to 1983, 4000 to 5000 cGy at 180 cGy per fraction; and 1984 to 1986, 3000 cGy in 10 fractions. The change was made to 3000 cGy in 10 fractions to reduce the inconvenience and expense associated with preoperative radiation therapy without sacrificing any improvement in local control or complication rates. There were no significant differences in the rates of local control, absolute survival, cause-specific survival, or complications between the three preoperative radiation therapy protocols. The results were compared for the 132 patients who underwent complete resection after preoperative radiation therapy and a series of 135 patients who underwent a complete resection alone for adenocarcinoma of the rectum at the University of Florida between 1959 and 1976. The results at 5 years, calculated by the product-limit method, for preoperative radiation therapy and surgery compared with surgery alone, respectively, were as follows: for local recurrence-free survival, 96% and 67%; for absolute survival, 66% and 40%; and for cause-specific survival, 77% and 50%. All of these differences are significant (p = 0.0001 or less). A subset of 56 patients with locally advanced lesions, based on tethering or circumferential involvement of the rectal lumen, treated with preoperative radiation therapy and surgery were compared with patients treated with surgery alone for stage B2 and C cancers. There was a significant improvement in local control and survival rates in the group irradiated before operation. There was no apparent increase in the incidence of postoperative complications in the patients irradiated before operation.

Adenocarcinoma↗
PubMed1992

Mandibular lingual releasing approach.

The mandibular lingual releasing approach to oral cavity and oropharyngeal tumors provides excellent visualization for resection while integrity of the mandibular arch is preserved. A lingual floor-of-mouth flap is created, which allows delivery of these structures directly into the neck without lip splitting, mandibulotomy, or mandibulectomy. The procedure was carried out on 15 patients between 1987 and 1991, with followup ranging from 2 to 50 months. Nine patients had received previous radiation, whereas planned postoperative radiation was administered to five patients. The visualization afforded by this technique was very good, in that 12 patients had clear margins of resection. Three patients had close margins; recurrent disease developed in one of these patients 18 months later. Twelve of the patients were able to maintain their weight with an oral diet alone. Four postoperative fistulae occurred, three of these were in patients who had not been previously irradiated. The single fistula that did not spontaneously heal occurred in a patient who had received previous radiation and was also on long-term corticosteroids. Mandibular osteoradionecrosis developed in two patients who received postoperative radiation. The complication rate after previous radiation is acceptable; however, there is risk of mandibular osteoradionecrosis after high-dose postoperative radiation.

Adult↗
PubMed1992

Preoperative irradiation and surgery for initially unresectable adenocarcinoma of the rectum.

Forty-two patients with initially unresectable rectal adenocarcinoma were treated with preoperative irradiation and surgery between March 1970 and March 1986 at the University of Florida (Gainesville, FL). No patient received adjuvant chemotherapy. All patients had follow-up for at least 5 years; 23 (55%) had follow-up for 10 years or more. Five patients (12%) underwent an exploratory laparotomy before irradiation; the remaining 37 patients were clinically thought to have unresectable disease. Eighteen patients had tumor fixation to one structure, and 24 patients (57%) had fixation to two or more structures. Lesions that exhibited impaired mobility but not complete fixation were considered to be clinically resectable and are not included in this series. The dose of preoperative irradiation ranged from 3,500 to 6,000 cGy at 180 cGy per fraction; 30 of 42 patients received 4,500 to 5,000 cGy and only 4 patients received less than 4,000 cGy. Forty-one patients were operated on 1 to 11 (mean 4.6) weeks after the completion of radiotherapy; 1 patient died of aspiration pneumonia after completing irradiation but before the planned resection. Resection of the rectal cancer was accomplished in 37 patients. Four patients were found to have extensive unresectable disease at laparotomy. Twenty-one patients had a complete resection: 11 were stage B2, and 10 were stage C2. Twenty patients had incomplete resection due to positive margins (8 patients), distant metastases with or without positive margins (8 patients), or no resection due to extensive disease (4 patients). Two patients died after the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1991

Time-dose factors in positive neck nodes treated with irradiation only.

This article describes an analysis of time-dose and clinical factors which affect the 2 year rate of control of cervical node metastases from squamous cell carcinoma of the head and neck following external beam radiotherapy in a series of 140 patients. We find that node diameter and normalized total dose are the most important factors, and that overall treatment time is not statistically significant.

Adult↗
PubMed1991

The role of radiation therapy in inverted papilloma of the nasal cavity and paranasal sinuses.

Between December 1969 and March 1985, seven patients with advanced biologically aggressive inverted or cylindrical cell papillomas were treated with irradiation at the University of Florida. Three patients were treated with radiation therapy alone, and four patients were irradiated either before (one patient) or after (three patients) resection. No recurrences were observed in six patients at 4.5, 7, 8, 8, 9, and 20 years following treatment (including two who died of intercurrent disease at 7 and 9 years after radiation therapy without evidence of recurrent tumor). One patient treated with irradiation alone for an advanced recurrent papilloma developed a local recurrence extending into the frontal lobe of the brain and died 17 months after radiation therapy. None of the patients experienced a significant complication of irradiation. Although surgery is generally the primary treatment modality for this disease, radiation therapy should be considered for patients with advanced, incompletely resected, or unresectable lesions.

Adult↗
PubMed1991

Primary subglottic cancer: results of radical radiation therapy.

Between October 1964 and December 1985, six patients with primary squamous cell carcinoma of the subglottis were treated with radical radiation therapy at the University of Florida. The disease was staged as Tis (one patient), T2N0 (two patients), and T4N0 (three patients). Local control was achieved with irradiation in four patients (66%) who were observed for 3.5, 4, 4, and 5 years after radiation therapy. Two patients whose tumors recurred at the primary site underwent salvage laryngectomy, which was successful in one patient.

Aged↗
PubMed1991

Pancoast tumor: radiation therapy alone versus preoperative radiation therapy and surgery.

This is a retrospective analysis of 73 patients with non-oat cell carcinoma of the lung presenting as a Pancoast tumor. All patients were treated with curative intent between October 1964 and September 1987 (minimum follow-up 2 years). The treatment plan consisted of preoperative radiation therapy (usually 3000 cGy in 2 weeks or 4500 cGy in 5 weeks) in 41 patients and radiation therapy alone (usually 6500-7000 cGy in 6.5-8.0 weeks) in 32 patients. In general, radiation therapy alone was reserved for poor-prognosis patients (extensive disease or medical inoperability). Although 41 patients were initially scheduled to receive preoperative radiation therapy and surgery, the surgery was not performed in 12 cases (29%) because of patient refusal (4 patients), poor response to radiation therapy (4 patients), distant metastasis (2 patients), or debilitation (2 patients). Separate calculations were carried out for the patients who completed the surgery as planned (preoperative radiation therapy and surgery) and the entire group originally scheduled for combined-modality therapy. There was no significant difference in the absolute or cause-specific survival rates between treatment groups, but severe complications were significantly more common in patients receiving combined therapy.

Adult↗
PubMed1991

Stage IB or IIA-B carcinoma of the intact uterine cervix greater than or equal to 6 cm in diameter: is adjuvant extrafascial hysterectomy beneficial?

This is an analysis of 150 patients with Stage IB or IIA-B carcinoma of the intact uterine cervix greater than or equal to 6 cm in diameter treated with irradiation alone (75 patients) or irradiation followed by surgery (75 patients) at the University of Florida between October 1964 and June 1983. Minimum follow-up in this series was 5 years. There was no significant difference in the distribution of prognostic factors between the two treatment groups. The 5-year local control rate was 74% with irradiation alone and 76% with irradiation and surgery. The 5-year survival rates for irradiation alone versus irradiation plus surgery were as follows: cause specific, 62% and 55%, and absolute, 54% and 52%. The proportion of patients who developed treatment complications necessitating hospitalization or a second operation was 4/75 (5%) after irradiation alone and 12/75 (16%) after irradiation and surgery. The authors conclude that the routine use of adjuvant extrafascial hysterectomy is not warranted in this patient population.

Adenocarcinoma↗